Electrolytic cell.



PATENTBD JUNE 20, 1 905..

I. F. KELLY. ELECTROLYTIC CELL.

APPLICATION FILED SEPT. o. 1904.

q Vi/hmme/o W llnrrnn STATES Patented June 20, 1905.

PATENT Fries.

JOHN F. KELLY, OF PITTSFIELD, MASSACHUSETTS, ASSIGNOR TO SOUTH- IVESTERN EXPLORATION COMPANY, OF ALAMOGORDO, TERRITORY OF NEIV MEXICO, A CORPORATION OF THE TERRITORY OF NEWV MEXICO;

ELECTROLYTIC CELL.

SPECIFICATION forming part of Letters Patent No. 792,597, dated June 20, 1905.

Application filed September 9, 1904. Serial No. 223.831.

To all whom, it may concern:

Be it known that I, JOHN F. KELLY, a citizen of the United States, residing at Pitts- Iield, county of Berkshire, and State of Massachusetts, have invented certain new and useful Improvements in Electrolytic Cells, fully described and represented in the following specification and the accompanying drawings, forming a part of the same.

This invention relates to improvements in electrolytic cells.

It is the obj cct of the invention to provide an electrolytic cell which shall reduce to a minimum the recombination of the products of decomposition of the electrolyte.

It is a further object of the invention to provide an electrolytic cell which may be worked continuously and permit of the direct recovery therefrom of the products of decomposition of the electrolyte.

In the accompanying drawings, Figure 1 is a plan view of an electrolytic cell for carrying out the invention. Fig. 2 is a vertical section of the cell on line X X of Fig. 1.

The electrolytic cell, as shown in the drawings, consists of three compartments, which compartments are electrically in series, the compartment for containing the electrolyte being positioned between the anode and cathode compartments, which receive and contain the products of the decomposition of the electrolyte. The electrolyte and the products of its decomposition are physically in, osmotic connection only, the liquids in the electrolyte-compartment and in the lateral compartments being separated by diaphragms, which diaphragms are composed, preferably, of the sulfates of the alkaline earths. Although the cell as it is proposed to use it and as it is shown in the drawings may be used in the decomposition of any electrolyte, it is especially adapted because of the arrangement of its parts for the decomposition of an electrolyte consisting of a solution of the alkaline sulfates, such as sodium and potassium sulfate, and the cell will be described as used in the decomposition of such sulfates,

the sulfate in the present instance being that of sodium.

Referring now to the drawings, 1 indicates a single electrolytic cell. The body of the cell may be of any suitable configuration, but preferably is rectangular in order to economize space where a large number of cells is to be used. The cell 1 is divided by diaphragms 2 into three compartments 4, 5, and 6, the compartment 5 being positioned between the compartments 4 and 6 and constituting the electrolyte-compartment which contains the solution to be decomposed. The compartment 6, as shown, is the anode-compartment, and is provided with an anode 7. The compartment i is, as shown, the cathode-compartment and is provided with a cathode 8. The three compartments are thus electrically in series that is, the current entering at the anode passes through the anode-compartment, then through the electrolyte-compartment, and through the cathodecompart ment to the cathode.

The anode and cathode are composed of any suitable material, depending largely on the solution which is to be subjected to the electrolytic action. In the present instance, where an. alkaline sulfate forms the electro lyte, the anode 7 is preferably of lead, as that metal is practically unaffected by the sulfuricacid which, as hereinafter explained, is formed in the anode-compartment. The cathode 8 is preferably of iron, as such metal is unaffected by the caustic soda or alkali formed, as hereinafter explained, in the cathodecompartment. Instead of iron, however, if desired, a cathode of carbon or like material, such as graphite, may be employed.

The electrolyte to be decomposed-such electrolyte in the present instance being a solution of sodium sulfateis contained in the central or electrolyte compartment 5, as above stated, and the liquid, preferably water, which receives the products of decomposition of the electrolyte, is contained in the compartments 4 and 6. These compartments are separated from each other by the diaphragms 2, hereinbeforc mentioned,which. keep the electrolyte from mingling with the products of its decomposition, and the diaphragms are, as shown, arranged to position the electrolyte between the products of its decomposition. The liquids in the several compartments are thereby effectually sepa rated and the loss of products owing to the 1 recombination is reduced to a minimum. Furthermore, by so positioning the electro lyte in relation to the products of its decomposition those products may be recovered directly from the anode and cathode compartments in which they are formed. If but one diaphragm. were used in the decomposition of an electrolyte composed of a solution of alkaline sulfate or if the cell em ployed were functionally but a one-compartment cell, a large amount of electrolyte would of necessity be present in the solution containing the products of dmwomposition, and if the cell were continuously worked the electrolyte would be carried away in large quantities with the products of its decomposition. To work a cell of such a character, it would be necessary to subject the electrolyte to the electrolytic action until the whole of the electrolyte had become decomposed and, to then remove and separate the products of the decomposition of the electrolyte before they could mingle and recombii-ie. By the use of the two diaphragnls and bypositioning the electrolyte between the products of its decomposition a continuous working is rendered possible and the waste of labor and current and the loss caused by recombination of the products of electrolysis is avoided and a very large percentage of the theoretical yield made recoverable directly.

The diaphragms 2, by which the cell is divided into three compartments, are of any suitable material. They should, however, permit the acid and basic ions to pass through them and be composed of a substance or substances not readily attacked by the electro lyte or the products or its decomposition. I have discovered that the sulfates of the alkaline earths are best adapted to fulfil these requirements. The diaphragms I prefer to employ, therefore, are composed of one or more sulfates of the alkaline earths, calcium sulfate being chosen preferably because of its cheapness, though barium sulfate may be used with equal effectiveness, or even a combination of the two. The diaphragms may be of any desired or conveniei'it shape or contour. Preferably, however, and as shown in Figs. 1 and 2, they are thin plates secured in the cell in any suitable manner, as by placing in slots If desired, however, they may be connected to form a box, as shown in plan in Fig.

The electrolyte is preferably a saturated solution, and the saturation of the solution is maintained either by placing crystals 9 of the salt of which the solution is formed in the compartment 5 or by running into the compartment in any suitable manner a saturated solution. hen the liquid in the anode and cathode compartments has become suffi ciently dense from the deposit therein of the products of the decomposition of the electrolyte, such liquid is drawn off at a fixed rate,

the level of the liquid being maintained in the anode and cathode compartments by supplying them with fresh liquid, the rate of supply being regulated to correspond with. the rate of the decomposition. of the electro lyte by the electric current in order to main.- tain at a constant density the liquids drawn. off from the anode and cathode compartments.

The operation of the cell, the electrolyte being a solution of sodium sulfate, is as follows: The solution of sodium sulfateis placed in the central compartment 5, and the two compartments 4 and 6 are filled. with water to the desired level, the diaphragms having first been placed in position, as hereinbefore described. The current is then supplied and the electrolytic action takes place. The electrolyteof sodic sulfate is decomposed thereby into a sodium and a sulfo-oxygen ion. The sodium ions are carried or pass by the action. of the current through the diaphragm into the cathode-compartment 4, thereby meeting the liquid in that compartment, which in the present instance is water. The reaction which takes place at the cathode may be expressed by the formula:

the caustic soda or alkali thereby formed going intosolution and the hydrogen rising and escaping at the cathode. The sulfooxygen ions (80,) are carried or pass by the action of the current through the opposite diaphragm into the anode compartment, meeting the liquid therein contained, which in the present instance is water. The reaction which takes place at the anode may be expressed by the following formula:

2so, 211,0 rnso, 0,,

sulfuric acid and oxygen being formed, the oxgyen rising and escaping at the anode.

From the above formulae it is seen that the cell is particularlyadapted for the decomposition of the sulfates of alkaline earths and. particularly adapted for the formation of the alkalies therefrom, and the yield of the al kali, as is apparent from. the reaction, being large.

It will be understood. that in. the normal operation of the cell the anode and cathode comp artm ents will contain solutions of respcctively the acid and basic products of the de composition of the electrolyte, such products of the decomposition being in contactlgwith the electrolyte through the diaphragms.

What is claimed is 1. In an electrolytic cell, the combination of an electrolyte-compartment containing an aqueous solution of the substance to be decomposed, anode and cathode compartments containing substantially only aqueous solutions of respectively the acid and basic products of decomposition of the electrolyte in the electrolyte-compartment, osmotic diaphragms interposed between the anode and cathode compartments and the electrolytecompartment by which mass mingling of the liquids in adjoining compartments is prevented and through which the products of the decomposition are in contact with the electrolyte, and an anode in the anode-cornpartment and a cathode in the cathodecompartment, the path of the current being from the anode through the acid product of decomposition, across the separatingdia phragm, through the electrolyte in the electrolyte-compartment, across the second separating-diaphragm and through the basic product of decomposition to the cathode.

2. In an electrolytic cell, the combination of an electrolyte-compartment containing an aqueous solution of the substance to be decomposed, anode and cathode compartments containing substantially only aqueous solutions of respectively the acid and basic products of decomposition of the electrolyte in the electrolyte-compartment, osmotic diaphragms interposed between the anode and cathode compartments and the electrolytecompartment by which mass mingling of the liquids in adjoining compartments is prevented and through which the products of the decomposition are in contact with the electrolyte, and an anode in the anode-compartment and a cathode in the cathode-compartment formed of substances insoluble in the solutions in their respective compartmen ts, the path of the current being from the anode through the acid product of decon1- position, across the separating-diaphragm, through the electrolyte in the electrolyte compartment, across the second separatingdiaphragm and through the basic product of decomposition to the cathode.

In an electrolytic cell, the combination of an electrolyte-compartment containing an aqueous solution of an alkaline sulfate to be decomposed, anode and cathode compartments containing substantially only aqueous solutions of respectively sulfuric acid and an alkaline hydrate, osmotic diaphragms interposed between the anode and cathode compartments and the electrolyte-compartment by which mass mingling of the liquids in adjoining compartments is prevented and through which the products of decomposition are in contact with the electrolyte, and an anode in the anode-compartment and a cathode in the cathode-compartment, the path of the current being from the anode through the acid, across the separating-diaphragm, through the solution of the sulfate in the electrolyte-compartment, across the second separating-diaphragm and through the alkaline hydrate to the cathode.

4. In an electrolytic cell, the combination of an electrolyte-compartment containing an aqueous solution of the substance to be decomposed, anode and cathode compartments containing substantially only aqueous solutions of respectively the acid and basic products of decomposition of the electrolyte in the electrolyte-eompartment, the electrolytecompartment being positioned between the anode and cathode compartments, osmotic diaphragms interposed between the anode and cathode compartments and the electrolyte-compartment by which mass mingling of the li uids in adjoining compartments is prevente d and through which the products of the decomposition are in contact with the electrolyte, and an anode in the anode-compartment and a cathode in the cathode-compartment, the path of the current being from the anode through the acid product of decomposition, across the separatingdiaphragm, through the electrolyte in the electrolyte-com partment, across the second separating-diaphragm and through the basic product of decomposition to the cathode.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

JOHN F. KELLY.

lVitne'sses:

WV. H. KENNEDY, P. B. PIIILIPP.

It is hereby certified that in Letters Patent N 0. 792,597, granted June 20, 1905, upon the application of John F. Kelly, of Pittsfield, Massachusetts, for an improvement in Electrolytic Cells, an error appears in the printed specification requiring correction, as follows: In line 47, page 2, the Word or, after the Word products, should read of; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 18th day of July, A. D., 1905.

[SEAL] F. I. ALLEN,

Commissioner of Patents. 

